Multimedia Broadcast Multicast Service (MBMS) is a Point-to-Multipoint (PTM) interface specification designed to provide efficient delivery of broadcast and multicast services within 3rd Generation Partnership Project (3GPP) cellular networks. Examples of MBMS interface specifications include those described in Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE) communication specifications. For broadcast transmission across multiple cells, the specifications define transmission over single-frequency network configurations. Intended applications include mobile TV, news, radio broadcasting, file delivery, emergency alerts, and others. When services are broadcasted by MBMS, all cells inside an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area transmit the same MBMS service. Services that can be provided using PTM can be referred to as PTM compatible services. As discussed herein, MBMS services and MBMS content are PTM compatible services that are provided via MBMS.
Users access these services and obtain the MBMS content through wireless communication devices such as cellular phones, tablets, laptops, and other devices with wireless transceivers that communicate with the base stations within the communication system. The base stations, sometimes referred to as eNodeBs or eNBs, provide wireless services to the wireless communication devices, sometimes referred to as user equipment (UE) or UE devices, within cells.
A user can access at least some multimedia services through a UE using either a Point-to-Point (PTP) connection or a Point-to-Multipoint (PTM) transmission. PTP services are provided using Unicast techniques and PTP transmissions are performed using MBMS communication in 3GPP systems. Accordingly, a PTM compatible service can be provided using either Unicast service or MBMS. In order to avoid inefficient use of resources, current specifications and proposals include provisions for tracking and evaluating the number of UEs that have been characterized by the network, at least for resource management purposes, as UEs that will receive the PTM compatible service. The network monitors the number of UEs accessing an MBMS service, congestion levels and other communication parameters, and makes appropriate adjustments to the network to maintain efficient use of communication resources. For example, resources are more efficiently allocated by only providing a specific PTM compatible service with MBMS when the number of wireless communication devices in connected mode (connected mode UEs) receiving the specific PTM compatible service using PTM is sufficiently high. When there are many users that are using, or will likely use, a particular PTM compatible service in the MBSFN area, then the network allocates resources to deliver the program by MBMS via PTM. In other words, if there are many users that are interested in getting a particular PTM compatible service and, therefore, are operating a wireless communication device that is receiving, or is likely to receive, the PTM compatible service in the MBSFN area, then the network allocates resources to deliver the specific PTM compatible service using PTM techniques. On the contrary, if there are a small number of users that are interested in and will use the particular PTM compatible service, it is more efficient to deliver the PTM compatible service using PTP techniques such as those used with a Unicast connection. When services are broadcasted by PTM using MBMS, all cells inside the MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area are required to broadcast the same information so the amount of wasted resource could be very large when very few wireless communication devices (UEs) are obtaining the service. In accordance with current specifications, therefore, a program or service is discontinued from PTM transmission when the size of the audience using wireless communication devices in connected mode decreases below a threshold. For activation of a service by PTM, the network evaluates the number of wireless communication devices which are PTM capable but which are receiving a given PTM compatible service via PTP such as through a Unicast service as well as devices that have been identified as devices that will receive the PTM compatible service. The network characterizes devices that are receiving the service or that are likely to receive the service as devices that will receive the service for purposes of resource management and determines the number of PTM capable wireless communication devices (UEs) that are characterized as devices that will receive the service. When that number of PTM capable wireless communication devices (UEs) exceeds a threshold, the service is provided using PTM.
In order for the network to receive reception status feedback from the wireless communication devices (UEs), the current 3GPP specifications specify Counting Procedures. A Counting Procedure is initiated by the network. A Multi-cell/multicast Coordination Entity (MCE) in the network sends a request to each eNodeB providing the specific PTM compatible service in the MBSFN area to send a Counting Request to the wireless communication devices (UEs). The Counting Request contains a list of specific PTM compatible service identifiers requiring wireless communication device (UE) feedback. The connected mode wireless communication devices (UEs) which are receiving, or interested in receiving, the identified content respond with a Counting Response message including the specific PTM compatible service identifiers that are of interest.
The current communication specifications, therefore, provide for a Counting Procedure that allows for the network to determine a number of wireless communication devices (UEs) in the connected mode that are interested in specific MBMS content. Proposals have been offered for counting wireless communication devices (UEs) in idle mode that are receiving, or will likely receive, a specific PTM compatible service.
The network also monitors the number of wireless communication devices (UEs) that are accessing a particular frequency and performs load balancing procedures to avoid congestion. For example, when a threshold percentage of total capacity is reached, the network applies procedures for reducing the number of wireless communication devices on the particular frequency.
Current 3GPP specifications specify a mechanism for providing MBMS frequency information to the wireless communication devices, where the MBMS frequency information allows a wireless communication device to determine the frequencies at which particular MBMS services are available. More specifically, the most 3GPP Revision 11 specification provides that base stations (eNBs) transmit MBMS Service Area Identification (SAI) frequency information using the System Information Block 15 (SIB15). The MBMS SAI frequency information provides information regarding the relationship between SAIs and frequencies. For example, the SAI frequency information includes the correlation between MBMS SAIs and frequency channels for all MBMS frequency channels for the serving base station (eNB) as well as for neighboring base stations (eNBs). The wireless communication also obtains a User Service Description (USD) which provides information related to the relationship between SAIs and MBMS services. For example the USD contains at least Temporary Mobile Group Identities (TMGIs) and MBMS Service Area Identities (SAIs) as well as an association between the TMGIs and the MBMS SAIs. The wireless communication device downloads the USD and may receive the USD from a base station in some circumstances. The MBMS frequency information which provides the relationship between MBMS services and frequencies can be determined based on the USD and the SAI frequency information.
Network changes result from the counting procedures, load balancing, and other network management may result in changes to the MBMS frequencies and services such that the frequencies carrying a particular MBMS service are changed. Accordingly, in some cases the network adjustments may result in changes in the frequency information related to MBMS services.